The White House and the Pentagon have acknowledged that the U.S. military launched a secret rescue mission in Yemen last week to rescue American Luke Somers who had been kidnapped by al Qaeda in the Arabian Peninsula for almost a year.

Somers was not able to be rescued because he had been moved two days before the daring raid from the cave where he and other hostages were being held by their captors.

Somers appeared today in a video released by the group where he pleaded for his release.

“We are aware of a video showing Luke Somers, a U.S. citizen held hostage by al Qaeda in the Arabian Peninsula (AQAP),” said Bernadette Meehan, the spokesperson for the National Security Council.

"Last month, the president authorized an operation to rescue Luke, who has been held hostage by AQAP in Yemen since September 2013, and a number of other hostages,” said Meehan.

“As soon as the U.S. government had reliable intelligence and an operational plan, the president authorized the Department of Defense to conduct an operation to recover Mr. Somers,” said Meehan.

“Regrettably, Luke was not present, though hostages of other nationalities were present and were rescued, said Meehan.

A U.S. counter-terrorism official told ABC News that two days before the raid was launched, Somers and several other hostages had been moved from the cave where he and several others were being held in a remote area of northeastern Yemen.

Last week, Yemen confirmed that a raid launched by its military forces had rescued six Yemenis, an Ethiopian and a Saudi held by AQAP.

In a separate statement issued today, Pentagon spokesman Rear Admiral John Kirby said the operation was conducted by American and Yemeni military forces “and involved air and ground components.”

A U.S. official has told ABC News that members of the Navy’s elite SEAL Team Six were part of the American special operations forces involved in the rescue mission.

Both Meehan and Kirby said they would not provide further details about the mission because it remains classified.

“The overriding concern for Mr. Somers’ safety and the safety of the U.S. forces who undertake these missions made it imperative that we not disclose information related to Mr. Somers’ captivity and the attempted rescue,” said Meehan. “The Department of Defense is acknowledging the fact of the operation now in order to provide accurate information given that it is being widely reported in the public domain.”

Kirby added that the U.S. government will use the “full breadth” of its military, intelligence and law enforcement capabilities to bring home Americans held hostage overseas.

“The United States will not tolerate the abduction of our people, and will work tirelessly to secure the safety of our citizens and to hold their captors accountable,” said Kirby.